Attorney General Alberto R. Gonzales said yesterday that he spoke with White House Chief of Staff Andrew H. Card Jr. immediately after learning that the Justice Department had launched a criminal investigation into the leak of a CIA operative's identity. But Gonzales, who was White House counsel at the time, waited 12 hours before officially notifying the rest of the staff of the inquiry.

Many details of the investigation led by special prosecutor Patrick J. Fitzgerald are unknown. Sources close to the case have said Fitzgerald is looking into possible conflicts between what President Bush's senior adviser Karl Rove and vice presidential staff chief I. Lewis "Scooter" Libby told a grand jury, and the accounts of reporters who spoke with the two men.

Gonzales said yesterday on "Fox News Sunday" that he is among the group of top current and former Bush administration officials who have testified to the grand jury about the unmasking of Valerie Plame, a CIA operative. Gonzales, who has recused himself from the case, would not discuss details of his testimony but said he learned about Plame's work from newspaper accounts.

In the New York Times yesterday, columnist Frank Rich cited news reports from 2003 that when Gonzales was notified about the investigation on the evening of Monday, Sept. 29, 2003, he waited 12 hours before telling the White House staff about the inquiry. Official notification to staff is meant to quickly alert anyone who may have pertinent records to make sure they are preserved and safeguarded.

Asked on CBS's "Face the Nation" about the column, Gonzales said the Justice Department had informed his office around 8 p.m. and that White House lawyers said he could wait until the next morning before notifying the staff. He did not say why he called Card.

"I specifically had our lawyers go back to the Department of Justice lawyers and ask them, 'Do you want us to notify the staff now, immediately, or would it be okay to notify the staff early in the morning?' And we were advised, go ahead and notify the staff early in the morning, that would be okay." He said most of the staff had left by the time the Justice Department called and that "no one knew about the investigation."

But he acknowledged telling one person: "the chief of staff. And immediately the next morning, I told the president. And shortly thereafter, there was notification sent out to all the members of the White House staff," Gonzales said.

Sen. Joseph R. Biden Jr. (D-Del.), appearing on the same program, questioned why Gonzales would not have notified the staff immediately by e-mail and suggested that Fitzgerald pursue whether Card may have given anyone in the White House advance notice of the criminal investigation.

"The real question now is, who did the chief of staff speak to? Did the chief of staff pick up the phone and call Karl Rove? Did the chief of staff pick up the phone and call anybody else?" Biden asked.

The case centers on the White House response in the days after July 6, 2003, when former ambassador Joseph C. Wilson IV accused the Bush administration of twisting intelligence on Iraq's weapons arsenal to justify war. In an op-ed piece, Wilson wrote that the government sent him to Niger to investigate assertions that Iraq had tried to acquire materials there for a nuclear weapon and that he had reported back, before the war, that no proof had been found to support the allegations.

Eight days after Wilson's article appeared, Robert D. Novak published a syndicated column suggesting that the administration did not take Wilson's findings seriously and noting that Wilson's wife -- Plame -- was a CIA operative who had suggested him for the trip.

After accusations that someone in the administration had jeopardized an operative's cover in political retaliation, the Justice Department appointed Fitzgerald in December 2003 to investigate.

Asked on CBS why he did not investigate the leak when it first became public, Gonzales said: "This is the kind of issue that I felt that we should wait and see whether or not there would be some kind of criminal investigation. And of course, there was."